fix: Add gridsome.server.js example

gridsome.config.js

@@ -1,7 +1,7 @@
-// This is where project configuration and installed plugin options are located. 
+// This is where project configuration and plugin options are located. 
 // Learn more: https://gridsome.org/docs/config
 
-// Changes here requires a server restart to work properly.
+// Changes here requires a server restart.
 // To restart press CTRL + C in terminal and run `gridsome develop`
 
 module.exports = {

gridsome.server.js

@@ -0,0 +1,12 @@
+// Server API makes it possible to hook into various parts of Gridsome
+// on server-side and add custom data to the GraphQL data layer.
+// Learn more: https://gridsome.org/docs/server-api
+
+// Changes here requires a server restart.
+// To restart press CTRL + C in terminal and run `gridsome develop`
+
+module.exports = function (api) {
+  api.loadSource(store => {
+    // Use the Data store API here: https://gridsome.org/docs/data-store-api
+  })
+}